The Lowell Sustainability Council made a presentation to the City Council at the March 22, 2022, City Council meeting. In that week’s newsletter I wrote that because so much else had happened at that meeting, I would revisit the Sustainability Council’s presentation at a future date. With no City Council meeting this week and with Earth Day falling on Friday (April 22), now seems like a good time to return to the Sustainability Council presentation.
That 2019 report includes the savings due to various sites that the City uses for solar panels, however, when accounting for the duration of time the site has been operating and the size of each site, there is a wide variation in the energy yield from site to site. Some appear to be operating as intended, but others are yielding a much lower power output. Could this be another unaddressed maintenance issue?
Every home or residence needs to be offered a free blower door test. No matter what power source you use none of it matters if you’re house is leaky. The passive house standard is set to .6ACH50 (.6 Air Changes per Hour at 50 pascals). Most homes built before 2000 are 12 to 15ACH50. Even after weatherization most homes will only be 4 to 5ACH50. To give you an idea a leaky house with 15ACH50 with a blower sized to a 5ton compressor covering 4000 sq feet of living space will operate 9 hours out of the day to maintain a temperature. At 4ACH50 it will operate 3 hours out of the day. At .6ACH50 it will operate for 14 minutes once every 16.5 hours. Even at 4ACH50 it cost about $300 a month to heat or cool that home. If that same home was .6ACH50 it would only cost 33$ a month! Passive house standards needs to be the new weatherization target. Do that one thing and everything else follows. It’s how you make a net zero home into a net negative; so if you got solar, you’ll always produce more power then you consume.
That 2019 report includes the savings due to various sites that the City uses for solar panels, however, when accounting for the duration of time the site has been operating and the size of each site, there is a wide variation in the energy yield from site to site. Some appear to be operating as intended, but others are yielding a much lower power output. Could this be another unaddressed maintenance issue?
Every home or residence needs to be offered a free blower door test. No matter what power source you use none of it matters if you’re house is leaky. The passive house standard is set to .6ACH50 (.6 Air Changes per Hour at 50 pascals). Most homes built before 2000 are 12 to 15ACH50. Even after weatherization most homes will only be 4 to 5ACH50. To give you an idea a leaky house with 15ACH50 with a blower sized to a 5ton compressor covering 4000 sq feet of living space will operate 9 hours out of the day to maintain a temperature. At 4ACH50 it will operate 3 hours out of the day. At .6ACH50 it will operate for 14 minutes once every 16.5 hours. Even at 4ACH50 it cost about $300 a month to heat or cool that home. If that same home was .6ACH50 it would only cost 33$ a month! Passive house standards needs to be the new weatherization target. Do that one thing and everything else follows. It’s how you make a net zero home into a net negative; so if you got solar, you’ll always produce more power then you consume.